Action for grand pianos



Nov. 19, 1935. F. GEORGE 2,021,449

ACTION FOR GRAND PIANOS Filed June 7, 1934 2 Sheets-Sheet 1 Nov. 19, 1935. F. L. GEORGE ACTION FOR GRAND PIANOS Filed June 7, 1934 2 Sheets-Sheet 2 n $1 hm H (a? 3% mm him. L i a v "r ava Patented Nov. 19, 1935 UNITED STATES PATENT OFFICE 12 Claims.

In the history of grand piano actions it appears that the double escapement repetition grand piano action was invented in the year 1821 by Sebastian Erard, of London, England,

5 and since that time, such action has remained the prototype of all grand piano actions used throughout the world; that the only improvements have consisted in minor details, the original principle being universally in use today.

This old type of action is extremely complicated and therefore necessarily expensive to construct and troublesome and costly to maintain and keep well regulated.

One of the characteristic features of this old and generally used type of grand piano action is that the lift of the hammer butt on the upper point of the jack is so designed that when the blow is completed, the escapement of the jack from under the hammer butt is toward the key board or front of the piano. The hammer in traveling upward to contact the wire under the impulse of the jack describes the arc of a circle and the round seat of the hammer butt which rides on the point of the jack is of wholly frictional engagement on the jack top throughout this movement until the heel of the jack contacts the regulating screw to effect its escapement from under the hammer butt. This friction at all times drags against and retards the upward movement of the hammer towards the wire. Further, when the heel of the jack contacts the regulating screw which causes its escapement from under the hammer butt, the top of the jack is suddenly dragged forward from under the hammer butt, tending to pull backward severely against the upward movement of the hammer towards the wire.

These are some of the disadvantages of the generally used construction, involving the kick or rotation of the upper end of the jack in an opposite direction to the arc of the swing of a hammer butt as the hammer moves upwardly to strike the strings. "This causes a certain friction at the upper end of the stroke when the jack is tilted due to the heel of the standard construction engaging a regulating pad.

Another objectionable and complicated feature of the generally used construction is in the mouning and action of the repeating lever which rides upwardly with the lifting jack, and after the jack is tilted towards the front, the repeating lever receives the hammer butt.

Another disadvantageous feature of the generally used construction is that the pivot for the hammers is above the bearing surface of the hammer butt and thus considerably above the contact of the jack with this butt. Such a construction requires the jack to oscillate instead of giving substantially a vertical thrust to the hammer. 5

Among the important objects and features of my invention is a hammer construction formed. with an elbow, the pivot being located so that a horizontal line through the pivot parallel to the strings is intersected substantially equally during the movement of the hammer butt on the top of the jack.

Another feature of my invention of importance involves mounting the rocker and the jack on the key using a capstan screw to regulate the position of the rocker. The jack is pivoted at its lower end to the free end of the rocker and the upper end of the jack engages the hammer butt and moves in such a direction that the arcuate movement of the hammer butt when the hammer is striking a string is in the same general direction as the movement of the upper end of the jack when it is kicked free by the spoon or heel of the jack engaging the regulat ing screw for the jack movement, thus at the moment that the jack is pulled away from the hammer butt both the upper end of the jack and the hammer butt are moving substantially in the same arcuate direction. This. reduces the friction on the hammer butt and does not retard the lifting movement of the hammer, but actually adds a further upward impulse of the jack to the hammer butt just at the instant when most beneficial, and, moreover, reduces the wear of the hammer butt facing. With my construction, the jack pivots towards the rear instead of towards the front of the piano.

Another important feature of my invention relates to the manner of mounting a repeating flange on the jack. This flange is made with an elbow having a substantially horizontal arm pivoted to the jack and having a vertical arm parallel to the face of the jack with a concave seat at the top to align with the top of the jack and to engage the hammer butt. The repeating flange is connected to an action spring by a cord loop and this action spring has a tension pullting the repeating flange towards the front of the keys. Therefore, at the moment the jack is released from the hammer butt, the seat of the repeating flange is brought into position to engage the hammer butt and support this with the hammer slightly below the strings; moreover, the back check at this instant engages the lower end of the hammer head. In the upward movement of the jack and repeating flange the hammer butt is supported by both the upper end of the jack and the base or seat of the repeating flange.

A much desired and most important feature of my invention relates to the combination of the action spring and its cooperating elements through the ability of the spring to transmit its tension to the jack and repeating flange in just the required proportion and at the correct instant of contact. The accompanying drawings will readily show that owing to the flexibility of the rotation of the silk cord and the great resiliency of the spring loop in combination, a graduated tension is exerted on both the repeating flange and the jack at just the instant that such changes become necessary, these changing degrees of tension being largely due to the formation of the elements surrounding the spring in combination, viz.:the permanent, stationary housing of the lower end of the spring in the rocker, the resiliency of the large loop in the center of the spring, and the rotation of the silk cord, creating a cooperative distribution in combination throughout the combined elements composing the repeating section of this action. This combination and its graduated cooperating operation of parts is believed to be entirely new.

My invention is illustrated in connection with the accompanying drawings, in which:

Fig. l is a transverse section through a piano key board showing sections of various portions and an elevation of the action with portions broken away and the keys and hammers shown in their rest or inactive position.

Fig. 2 is a similar view to Fig. l with various portions shown broken away, illustrating the action at the end of the stroke of a key and after the hammer has struck a string.

In the drawings the key frame is designated by the numeral ll having the balance rail I2 mounted thereon, at which rail the keys [3 are fulcrumed. Such keys may be fulcrumed in the ordinary manner or by the improved construction set forth in my copending application entitled Key and key frame for piano, Serial Number 729,414, filed June '7, 1934. The rest rail and pad M are illustrated on the key frame. The key frame also supports a metal bracket I5, which bracket has a seat l5 for the hammer flange rail 11. The hammer stem I8 is mounted on this rail and pivotally connected to the stem is the hammer [9. A feature of my hammer is that it has an elbow forming a short stem 2| to which the pivot 2?. is connected and a long arm 23 having the hammer butt 24 is secured to the hammer in the usual manner. It will be noted by my construction that the pivot 22 can never be above the hammer butt or above the point of contact of the hammer butt and the jack hereinunder detailed. The bracket !5 also forms a support for the hammer rest rail. 25 and for a regulating rail 26, through which extends the regulating screw 2! having the regulating screw cloth 28 at its lower end.

My invention differs radically from prior piano actions in having a flange 29 secured to the key and arocker an mounted on the flange. I change the position of the capstan screw 3| which screw is provided with a screw driver kerf 32 at the top and pin holes 33 on the side of the head, said capstan screw now being closer to the fulcrum of the key. This screw is adjustable in the key and passes through a perforation 34 adjacent one end of the rocker, the rocker being pivoted at substantially its center. A stiff spiral spring washer 35 spaces this end of the rocker from the key.

The jack 36 is pivoted adjacent its lower end to the rear end of the rocker, the upper end having the usual type of fiat face 31 slightly sloping, 5 and is provided with a jack stop cloth 38 mounted in the slot 39 cut into an extension on top of the jack. This cloth is designed to rest against the side face of the hammer butt when the action is at rest. A spoon 40 formed of metal is 10 driven into the lower end 5! of the jack and this has a spoon end 1 2 designed to contact with the cloth 28 of the regulating screw 2'! at the comletion of the stroke of the key. Metal spoons are often used in customary practice. 15

The repeating flange designated by the assembly numeral 43 has a pair of substantially horizontal arms 44 pivoted at 45 to an extension 46 on the back of the jack. A substantially vertical arm 4'? extends upwardly from the elbow por- 20 tion 48 and has a seat 49 at the top formed slightly concave to engage the hammer butt 24.

A cloth pad 50 is secured in a slot in the inside face of the upright arm 4'! of the repeating flange and is designed to engage a regulating screw 5| 25 which is threaded through the upper end of the jack and has an enlarged head 52 to engage the pad 50. This screw is provided with a screw driver kerf at its outer end.

An important f ature of my invention relates 80 to the construction and mounting of the action spring designated by the assembly numeral 53. This spring has a loop 54 formed substantially at the center. The upper portion 55 has a book 55 over which engages a silk cord loop 51, which 36 loop is plugged into the heel on the elbow portion of the repeating flange as indicated at 58. The lower portion 59 of the action spring has an eye 69 coiled around a pin 6|. Between the coil and the pin there is a cloth bushing 62. This 40 pin extends across a slot 63 in the forward part of the rocker. A forward extension 64 of the action spring extends from the coil forwardly in the slot 83 and is engaged by an adjusting screw E5 threaded through the forward end porl5 tion of the rocker. This has a screw driver kerf at its end. The pivot for the rocker 68 is on substantially its mid position considered vertically.

The manner of operation and functioning of my invention is as follows:

When the action and key are at rest the various parts occupy, when adjusted, approximately the position shown in Fig. 1. On striking or depressing a key, the rocker with the jack is elevated, the hammer butt being supported substantially equally by the upper end of the jack and the bearing faceof the repeating flange. As the hammer moves upwardly the hammer butt swings in a circle, the center of which is the pivot 22. This movement develops a type of rolling action between the surface of the hammer butt and the upper bearing surface of the jack. The direction of rolling movement of the surface of the hammer butt is towards the rear of the action. The jack has substantially a vertical movement except for 65 the slight horizontal movement of the hammer butt. At the top of the stroke the spoon end 42 of the jack heel 46 engages the regulating screw cloth 28. This gives a quick rearward oscillation of the upper end of the jack and this arcuate movement of the jack on its pivot is in a rearward direction similar to the rearward path of movement of the bearing surface of the hammer butt. The impetus given by the rising jack and the repeating flange causes the hammer head to strike the string. On dropping away from the string the hammer butt is mainly supported by the upper bearing surface of the repeating flange and the hammer head is brough into frictional engagemerit with the back stop mounted on the key, the various elements being in substantially the position shown in Fig. 2 at the end of a stroke.

When the jack is at the end of a stroke and tilted rearwardly due to the contact of the jack heel 40 with the cloth 28 of the regulating screw 21, the action spring gives a pull on the repeating flange swinging this slightly on its pivot 45 to receive the hammer butt on its upper bearing surface. This spring has additional resiliency over the ordinary type of action springs in having the loop 45 and is readily adjustable through the medium of the adjusting screw 65 which acts as a lever end to vary the tension on the silk loop 51. The correct position of the rocker 30 may be readily regulated by the capstan screw 3| either by using a screw driver in the screw driver kerf of the screw 3| or in the pin holes 33, these pin holes being accessible without removing the action from the piano. Also, the adjusting screw 65 may be readily reached while the key frame is in the piano. The adjusting screw 5| in the head of the jack is for the purpose of regulating the relative position of the upper or bearing surface of the repeating flange and the upper supporting end of the jack. The regulating screw 21 is for the purpose of timing the release of the jack from the hammer butt at the proper moment in the stroke of the key, jack and hammer.

When the action is at rest, that is, when the key I3 is in the position shown in Fig, l, the adjustment should be made such that the hammer butt is substantially equally supported by the upper end of the jack and the bearing surface of the repeating flange, Then, on the upward stroke of the action when the key is depressed, the jack and repeating flange both function in lifting the hammer, the hammer being given its final impelling stroke by the jack at substantially the instant the jack is tilted rearwardly due to the jack heel engaging the cloth 28 on the arh'usting screw 21. The action spring 53 then pulls the repeating flange slightly away from the jack so that its upper surface 49 catches the hammer butt on the drop of the hammer. When the rear end of the key is lowered by releasing the pressure on the front end, the hammer has a slight upward movement before it again engages on the upper end 31 of the jack. With my construction repeated notes may be struck without the key returning to its rest position shown in Fig. 1 and with a very slight movement of the key.

The jack stop cloth 38 on top of the jack has the function of a separate jack stop but in this case it engages the hammer butt and thus limits the inward pivoting movement of the jack.

One of the chief features in the successful operation of the hammer spring 53 is due to the ability to distribute its entire tension from the one hooked end, throughout the two different combined elements-the jack and the repeating flange-and in such a controlled manner that owing to the correct mechanical distribution of parts, said tension influence is necessarily and decidedly distributed in a much greater proportion throughout the one member-the repeating flange-than upon the other element, the jack; each element, however, receiving just the right proportion of the spring tension influence.

This type of combination spring and spring tension control and distribution is new and has never before appeared in piano action construction.

An important feature of making the jack heel 40 of metal is that this can be slightly bent by using pliers to make an approximate adjustment as to the release of the jack from the hammer butt and fine adjustment may be made by the adjusting screw 21.

Various changes may be made in the details of construction without departing from the scope of the invention as defined by the appended claims:

I claim:

1. In a piano having a pivotally mounted hammer with a hammer butt and a fulcrumed key, a rocker pivotally mounted on the key and extending longitudinally thereof above the top of the key, means to adjust the rocker as to the key, a jack pivotally connected to one end of the rocker and having a contact surf ace at its upper end to engage the hammer butt, an adjustable stop, a jack heel device on the jack to engage the stop at the end of a stroke of the key to rock the jack on its pivot, the motion of the contact surface and the jack when so rocked being in a direction away from the pivot of the hammer, and a repeating means mounted on the jack to engage the hammer butt on the top of the jack.

2. In a piano having a pivotally mounted hammer as claimed in claim 1, the repeating means comprising a repeating flange having a lower portion pivoted to the jack and an upwardly ex tending pcrtion normally having a contact face to engage the hammer butt when the key is in its rest position, said contact face of the repeating flange being positioned to contact the hammer butt on the drop of the hammer after the stroke of the key, and an action spring connected to the rocker and flexibly connected to the repeating flange.

3. In a piano having a pivotally mounted ham.- mer with a hammer butt and a fulcrurned key combined with a flange extending upwardly from the key and having arocker pivotally mounted thereon at substantially its center, the rocker extending longitudinally of the key, a jack pivotally mounted on one end of the rocker, an adjusting screw connecting the opposite end of the rocker and the key, an adjustable stop screw, a heel on the lower end of the jack and extending laterally therefrom to engage the adjusting screw, the jack having an upper contact surface to engage the hammer butt, a repeating flange having a lower section pivotally connected to the jack and an upper.section at right angles thereto having an upper contact face to normally engage the hammer butt, an action spring connected between the repeating flange and the rocker.

4. In a piano having a pivotally mounted hammer as claimed in claim 3, the action spring having upper and lower sections connected by a loop, the upper section being connected to the repeating flange by a flexible cord, the lower portion of the action spring being pivoted on a pivot in the rocker and having an extension and an adjusting screw engaging said extension.

5. In a piano having a pivotally mounted hammer as claimed in claim 3, the repeating flange having its lower portion connected to the upper portion by a substantially right angular elbow and an adjusting screw extending through the upper end of the jack -to vary the position of the contact surface of the repeating flange relative to the jack.

6. In a. piano as claimed in claim 3, a jack stop cloth secured to the upper portion of the jack and adapted to engage the hammer butt.

'7. In a piano, the combination of a pivotally mounted hammer having a hammer butt, a fulcrumed key, a jack, means forming a pivotal mounting for the jack on the key, a repeating device movably mounted on the jack, an action spring, means forming an adjustable mounting for the lower end of the action spring on the key, and a connection from the upper end of the action spring to the said repeating device tensioned to urge the jack and the repeating device towards the front of the key and a releasing means operative on the jack on completion of the stroke of a key to move the jack rearwardly as regards the hammer butt.

8. In a piano, the combination of a iulcrumed key, a flange secu'ed thereto, a rocker pivotally mounted on the flange and having a perforation at its forward end, a capstan screw extending through the perforation and threaded into the key forward of the said flange, a coiled spring between the forward end of the rocker and the key, a jack pivoted to the rear end of the rocker, a hammer pivotally mounted and having a hammer butt engaged by the jack and an action spring adjustably mounted on the rocker and having a connecting means at its upper end to the upper portion of the jack.

9. In a piano having a pivotally mounted hammer with a hammer butt fixed thereto and a fulcrumed key combined with a jack, a supporting means to pivotally and adjustably mount the jack on the key, a tilting means for the jack and an adjustable stop to be engaged thereby, a repeating device mounted on the jack, an action spring having its lower end secured with an adjustable relation to the supporting means, and having its upper end connected to said repeating device to urge both the repeating device and the jack in the same direction of movement.

10. In a piano as claimed in claim 9, the hammer having an elbow with a short depending end forming the hinge mounting and a long arm, the hammer butt being secured to the lower side of the long arm and the upper end of the jack having a jack stop cloth positioned to engage the hammer butt and limit the swinging movement of the jack under the influence of the action spring, by contacting the hammer butt when in its lowered position.

11. In a piano having a pivoted hammer with a hammer butt fixed thereto, a fulcrumed key, a rocker actuated by the key, a jack pivotally mounted to the rocker and having a surface on its upper end to contact the hamer butt, means to operate the jack at the end of the stroke of the key to move the contact end of the jack away from the hammer butt with a movement away from the pivot of the hammer, a repeating flange pivotally connected to the jack and having an end to engage the hammer butt, an action spring having one end connected to the repeating flange and the other end connected to the rocker to lower the contact end of the repeating flange when the jack is released from the hammer butt, whereby the lower end of the repeating flange receives the descending hammer butt.

12. In a piano having a pivoted hammer, the hammer having a stem with a hammer head thereon and an elbow with a downturned end, the downturned end of the elbow having the pivot, a hammer butt fixed to the stem adjacent the elbow, a pivotally mounted rocker, a jack pivoted to the rocker, the jack having a contact end to engage the hammer butt, 2. fulcrumed key operatively connected to the rocker to actuate the jack, means coacting with the jack to release the jack from the hammer butt at the upper end of a stroke, the hammer butt resting on the jack when the key is at rest with the contact surfaces of the hammer butt and of the jack being in substantially a horizontal plane through the pivot of the hammer, an L-shaped repeating flange having one arm pivotally connected to the jack and the other arm having a contact end to engage the hammer butt, an action spring having a connection to the repeating flange and an adjustable connection to the rocker, the said action spring moving the repeating flange to lower its upper end at the end of a stroke when the jack is removed from the hammer butt whereby the repeating flange receives the hammer butt after the hammer has completed its striking movement.

' FRANK L. GEORGE. 

